Aggregate Surface Porosity and Its Relationship to Asphalt Absorption As Revealed by Gray Relational Analysis

The mercury intrusion test was conducted with an automatic mercury porosimeter, and the pore characteristics of five types of aggregates commonly used in road construction were analyzed using mercury injection data obtained under different pressures. The amount of asphalt that infiltrated the aggregate pores under an asphalt-aggregate ratio of 4% was experimentally and numerically determined, and the influence of aggregate pore characteristics on the amount of asphalt that infiltrated the aggregate pores was analyzed using gray relative theory. Aggregate aperture ranged from approximately 0.01 to 334 mu m, and the aggregate pores can be classified into large, medium, small, and micropores according to their volume distribution. The volume distribution decreased in the following order: large > medium > small pores; the micropore volume was nearly negligible. Among the factors of pore surface area, pore volume, porosity, and average pore size, the extent of influence on absorption capacity of asphalt is porosity > pore volume > pore surface area > average pore diameter.